Data warehouses store information from a variety of data sources. A data warehouse can store current or historical data. Data in the data warehouse can be analyzed to determine a wide variety of different types of information.
Map Reduce is programming model for processing data in parallel. Map Reduce allows for distributed processing of the map and reduction operations. Provided that each mapping operation is independent of the others, all maps can be performed in parallel—though in practice this is limited by the number of independent data sources and/or the number of CPUs near each source.